Adjustable interbody fusion devices

ABSTRACT

Interbody fusion devices, insertion tools, methods for assembling an interbody fusion device, and methods for inserting a medical device between two vertebral bodies are disclosed. The interbody fusion device includes a base member, a top member, and at least one movement mechanism. The base member includes at least one of a pivot cylinder and a hinge channel. The top member includes at least one of a pivot cylinder and a hinge channel. The at least one pivot cylinder of the base member engages the at least one hinge channel of the top member and the at least one pivot cylinder of the top member engages the at least one hinge channel of the base member. The at least one movement mechanism engages the top member and the base member. Also disclosed are a vertebral spacer device and an interbody spacer system including an insertion tool and an interbody fusion device.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a U.S. National Stage Filing under 35 U.S.C. 371from International Patent Application Serial No. PCT/US2014/037884,filed 13 May 2014, published as WO 2014/186384 A2 on 20 Nov. 2014, whichclaims priority benefit under 35 U.S.C. § 119(e) to U.S. provisionalapplication No. 61/822,620 filed May 13, 2013, each of which are herebyincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates generally to general surgery, orthopedicand neurosurgical implants used for insertion within a space betweenhard tissue structures, and more specifically, but not exclusively,concerns devices implanted between bones to replace resected, fracturedor diseased structures and to maintain or reestablish proper spacingbetween two bones.

BACKGROUND OF THE INVENTION

Damage or disease that affects the integral structure of a bone or otherstructures, may lead to neurologic impairment or loss of structuralsupport integrity with possible permanent damage to the surrounding softtissue and adjacent neurologic, vascular and systemic structures.Maintaining or reestablishing anatomic spacing within a bone structureor other structural tissue is critical to ensuring continuedfunctionality and mobility of the patient and avoidance of long-termserious neurological, vascular or other systemic impairments. Pleasenote that the terms “implant” and “device” may be used interchangeablyand have the same meaning herein.

SUMMARY OF THE INVENTION

Advancement of the state of interbody fusion devices and implants andthe surgical management relating to the clinical presentation of damagedtissue structures within the body is believed desirable. Exampleembodiments of the invention that satisfies the need for improvements toan expandable interbody fusion device used to treat patients sufferingfrom either diseased or damaged disc or other tissue structures includesa superior member coupled to a body member.

The present invention provides in one aspect, an interbody fusion deviceincluding a base member, a top member, and at least one movementmechanism. The base member includes at least one pivot cylinder and atleast one hinge channel. The top member includes at least one pivotcylinder and at least one hinge channel. The at least one pivot cylinderof the base member engages the at least one hinge channel of the topmember and the at least one pivot cylinder of the top member engages theat least one hinge channel of the base member. The at least one movementmechanism engages the top member and the body member.

The present invention provides in another aspect, an interbody spacersystem including an insertion tool and an interbody fusion device. Theinsertion tool may include a handle, an insertion end, at least one tubeextending distally away from the handle and connecting the handle andthe insertion end. The tool may also include a securement mechanism andat least one adjustment mechanism coupled to the handle and extendingthrough the at least one tube and protruding from the insertion end. Thetool may further include a first knob for actuating the securementmechanism and at least one second knob for actuating the adjustmentmechanism. The interbody fusion device may include an inferior member, asuperior member, and at least one movement mechanism engaging thesuperior member and the inferior member. The inferior member includes atleast one of a pivot cylinder and a hinge channel, a tool alignmentopening for receiving the securement mechanism of the insertion tool,and an adjustment opening adjacent the tool alignment opening forreceiving the at least one adjustment mechanism. The superior memberincludes at least one pivot cylinder and a hinge channel. The at leastone pivot cylinder of the inferior member engages the at least one hingechannel of the superior member and the at least one pivot cylinder ofthe superior member engages the at least one hinge channel of theinferior member.

The present invention provides in yet another aspect, a base member, atop member, and at least one movement mechanism. The base memberincludes at least one pivot cylinder. The top member includes at leastone hinge channel, at least one contact area on a bottom surface of thetop member, and at least one stop pin extending out from the at leastone contact area. The at least one pivot cylinder engages the at leastone hinge channel to allow pivoting motion. The at least one movementmechanism engages the at least one contact area of the top member andthe base member to facilitate movement therebetween.

Further, additional features and advantages are realized through thetechniques of the present invention. Other embodiments and aspects ofthe invention are described in detail herein and are considered a partof the claimed invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. It is emphasized that, in accordance with thestandard practice in the industry, various features are not drawn toscale. In fact, the dimensions of the various features may bearbitrarily increased or reduced for clarity of discussion. Theforegoing and other objects, features and advantages of the inventionare apparent from the following detailed description taken inconjunction with the accompanying drawings in which:

FIG. 1 is a posterior perspective view of one embodiment of anexpandable interbody fusion device, in accordance with an aspect of thepresent invention;

FIG. 2 is a posterior perspective view of the expandable interbodyfusion device of FIG. 1 with the moveable members extended, inaccordance with an aspect of the present invention;

FIG. 3 is a posterior view of the expandable interbody fusion device ofFIG. 1 with the moveable members extended, in accordance with an aspectof the present invention;

FIG. 4 is an exploded view of the expandable interbody fusion device ofFIG. 1, in accordance with an aspect of the present invention;

FIG. 5 is a superior perspective view of the expandable interbody fusiondevice of FIG. 1, showing only the base or bottom member, in accordancewith an aspect of the present invention;

FIG. 6 is an inferior perspective view of the expandable interbodyfusion device of FIG. 1, showing only the top or superior member, inaccordance with an aspect of the present invention;

FIG. 7 is an exploded view of the expansion mechanism of the expandableinterbody fusion device of FIG. 1, in accordance with an aspect of thepresent invention;

FIG. 8 is a posterior elevational view of the expandable interbodyfusion device of FIG. 1 without the top member, showing the expansionassemblies seated in the transparent base member, extended and tilted toaccommodate the slanted top member, in accordance with an aspect of thepresent invention;

FIG. 9 is a partially exploded posterior perspective view of theexpandable interbody fusion device of FIG. 1 showing the lockingmechanism being inserted into the interbody fusion device, in accordancewith an aspect of the present invention;

FIG. 10 is an isometric view of the locking mechanism of FIG. 9, inaccordance with an aspect of the present invention;

FIG. 11 is a posterior perspective view of the expandable interbodyfusion device of FIG. 1 with a transparent base member showing a driverod and locking mechanism, in accordance with an aspect of the presentinvention;

FIG. 12 is a top perspective view of an expansion tool, in accordancewith an aspect of the present invention;

FIG. 13 is a top perspective view of the expansion tool of FIG. 12 witha transparent handle portion and housing portion, in accordance with anaspect of the present invention;

FIG. 14 is an exploded view of the expansion tool of FIG. 12, inaccordance with an aspect of the present invention;

FIG. 15 is a perspective view of one embodiment of an expandableinterbody fusion device, in accordance with an aspect of the presentinvention

FIG. 16 is a perspective view of the expandable interbody fusion deviceof FIG. 15 with the moveable members extended, in accordance with anaspect of the present invention;

FIG. 17 is a posterior view of the expandable interbody fusion device ofFIG. 15 with the moveable members extended, in accordance with an aspectof the present invention;

FIG. 18 is an exploded view of the expandable interbody fusion device ofFIG. 15, in accordance with an aspect of the present invention;

FIG. 19 is a superior perspective view of the expandable interbodyfusion device of FIG. 15, showing only the base or bottom member, inaccordance with an aspect of the present invention;

FIG. 20 is an inferior perspective view of the expandable interbodyfusion device of FIG. 15, showing only the top or superior member, inaccordance with an aspect of the present invention;

FIG. 21 is an exploded view of the expansion mechanisms of theexpandable interbody fusion device of FIG. 15, in accordance with anaspect of the present invention;

FIG. 22 is a posterior perspective view of the expandable interbodyfusion device of FIG. 15 without the top member, showing the expansionassemblies seated in the transparent base member, extended and tilted toaccommodate the slanted top member, in accordance with an aspect of thepresent invention;

FIG. 23 is a perspective view of the expandable interbody fusion deviceof FIG. 15 with a transparent base member showing a drive rod andlocking mechanism, in accordance with an aspect of the presentinvention;

FIG. 24 is a perspective view of the expandable interbody fusion deviceof FIG. 15 and an expansion tool, in accordance with an aspect of thepresent invention;

FIG. 25 is a perspective view of the expansion tool of FIG. 24, inaccordance with an aspect of the present invention;

FIG. 26 is a truncated anterior view of the attachment end of theexpansion tool of FIG. 24, in accordance with an aspect of the presentinvention;

FIG. 27 is a perspective view of the expansion tool of FIG. 24 with atransparent outer housing, in accordance with an aspect of the presentinvention;

FIG. 28 is a truncated distal view of the handle end of the expansiontool of FIG. 24 with a transparent outer housing, in accordance with anaspect of the present invention;

FIG. 29 is an exploded view of the tool of FIG. 24, in accordance withan aspect of the present invention;

FIG. 30 is an exploded view of the handle portion of the tool of FIG.24, in accordance with an aspect of the present invention;

FIG. 31 is an exploded view of the insertion portion of the tool of FIG.24, in accordance with an aspect of the present invention;

FIG. 32 is a perspective view of the expandable interbody fusion deviceof FIG. 15 and the tool of FIG. 24, in accordance with an aspect of thepresent invention;

FIG. 33 is a perspective view of the tool of FIG. 24 engaging theexpandable interbody fusion device of FIG. 15, in accordance with anaspect of the present invention;

FIG. 34 is a truncated view of the tool of FIG. 24 inserted into theimplant of FIG. 15, in accordance with an aspect of the presentinvention;

FIG. 35 is a perspective view of the tool of FIG. 24 engaging theexpandable interbody fusion device of FIG. 15 in an expanded position,in accordance with an aspect of the present invention;

FIG. 36 is an isometric view of an expandable interbody fusion devicewith a transparent top member and the moveable member extended, inaccordance with an aspect of the present invention;

FIG. 37 is an exploded superior view of the expandable interbody fusiondevice of FIG. 36, in accordance with an aspect of the presentinvention;

FIG. 38 is an exploded inferior view of the expandable interbody fusiondevice of FIG. 36, in accordance with an aspect of the presentinvention;

FIG. 39 is a perspective view of a partially open expandable interbodyfusion device, in accordance with an aspect of the present invention;

FIG. 40 is an exploded view of the expandable interbody fusion device ofFIG. 39, in accordance with an aspect of the present invention; and

FIG. 41 is an inferior perspective view of the expandable interbodyfusion device of FIG. 39, showing only the top or superior member, inaccordance with an aspect of the present invention.

DETAILED DESCRIPTION FOR CARRYING OUT THE INVENTION

Generally stated, disclosed herein is an interbody fusion device orinterbody device that typically includes a top member, a base member,and at least one expansion mechanism. Further, the interbody fusiondevice may include an extendable/retractable member or expansionassembly and an expansion tool for expansion and contraction of theinterbody device. The retractable member extending in a verticaldirection. As used herein, the terms “interbody fusion device,” “medicaldevice,” “device,” “interbody device” and “implant” may be usedinterchangeably as they essentially describe the same type of device.Further, the corresponding expansion tool may also be referred to as“tool” or “instrument” and these terms may be used interchangeably.Finally, described herein is a surgical method for using the interbodyfusion device to maintain a space between two vertebral bodies within apatient suffering from a diseased or damaged disc or spinal column.

In this detailed description and the following claims, the wordsproximal, distal, anterior, posterior, medial, lateral, superior andinferior are defined by their standard usage for indicating a particularpart of a bone or implant according to the relative disposition of thenatural bone or directional terms of reference. For example, “proximal”means the portion of an implant nearest the torso, while “distal”indicates the portion of the implant farthest from the torso. As fordirectional terms, “anterior” is a direction towards the front side ofthe body, “posterior” means a direction towards the back side of thebody, “medial” means towards the midline of the body, “lateral” is adirection towards the sides or away from the midline of the body,“superior” means a direction above and “inferior” means a directionbelow another object or structure.

As depicted in FIGS. 1-3, the general arrangement of an adjustableinterbody fusion device 100, in one embodiment, includes a base member110, at least one moveable top member 130, and an expansion mechanism140. The top member 130 may be detachably coupled to the body member110. As used herein, the terms “base member,” “body member,” “bottommember” and “inferior member” may be used interchangeably herein as theyessentially describe the same element of the device. Also as usedherein, the terms “top member,” “superior member,” and “moveable member”may be used interchangeably as they essentially describe the sameelement of the device. The device 100 as seen in FIG. 1 may have, forexample, a generally rectangular geometry with various configured longsides to facilitate insertion and bone coverage. Although it would beunderstood by one skilled in the art that other outside configurationscan be used.

As seen in FIGS. 1 and 2, base member 110 may have at least one throughhole or central opening 102 for insertion of bone graft materialdisposed on the inferior and superior bone contacting surfaces 104. Theopening 102 typically extends through both bone contacting surfaces 104of the base and top members 110, 130 and into the inner cavity of theassembled device 100. The size and configuration of the opening 102allow the surgeon to place bone graft material inside the implant 100 toachieve a continuous fusion between the inferior and superior vertebralbodies.

As shown in FIG. 1, the superior and inferior bone contacting surfaces104 may be generally parallel to each other. However, the expansionmechanism or movement mechanism 140 (these names may be usedinterchangeably) will allow the user to angle or raise one side of thebone contacting surface 104 of the top member 130 relative to the bonecontacting surface 104 of the base member 110 as seen in FIGS. 2 and 3,wherein the near side is fully expanded and the far side remainsstationary. FIGS. 1-4 show the bone contacting surfaces 104 to haveteeth-like or tine structures projecting away from the superior andinferior surfaces. One skilled in the art would recognize that othersurface treatments may be applied to the bone contacting surfaces 104 toenhance fixation with the opposing bone surface. Although not shown, itis understood by one skilled in the art that modular bone contactingsurfaces, caps or plates may be used to provide for varying types ofbone contacting surfaces and structures, including, but not limited tosharp tines, porous coatings, biomaterial or ingrowth surfaces, andridge structures. It is also understood that the bone contactingsurfaces 104 may be coated with nano-surfacing, bioactive or bone/tissueingrowth coatings.

As seen in FIGS. 4 and 5, the base member 110 may also include a toolalignment opening 112 on the posterior end of the base member 110, atool attachment opening 114 in the tool alignment opening 112, and anadjustment opening 116 on the posterior end of the base member 110 andwhich may be adjacent to the tool alignment opening 112, as seen inFIGS. 1-5. The base member 110 may also include at least one hole orlumen 118 near the proximal and/or distal ends of the base member 110 tohouse an expansion mechanism 140, which will be discussed in greaterdetail below. In one embodiment, as illustrated in FIGS. 1-11, the basemember 110 may include, for example, two holes 118, although only onehole 118 as well as more than two holes 118 are also contemplated. Theholes 118 may have a smooth vertical wall to facilitate insertion andunrestricted rotation of a cylindrical gear 150 of the expansionmechanism 140. The holes 118 of the base member 110 may also include aninternal circumferential shoulder 120 and a channel 122 extending fromthe adjustment opening 116 interiorly along a lateral side of the basemember 110 to engage the holes 118. The base member 110 may also includeat least one pivot cylinder 124, at least one hinge channel 126, and anopening 128. The at least one pivot cylinder 124 and the at least onehinge channel 126 may alternate as depicted in FIGS. 4 and 5.

As seen in FIGS. 4 and 6, the top or superior member 130 also includesan undersurface 132 with at least one relief area 134 that is adjacentto the central opening 102. The central opening 102 may be configured topermit the insertion of bone graft material into the inner cavity of theimplant 100 prior to or after implantation. In one embodiment, asillustrated in FIGS. 1-11, the top member 130 may include, for example,two relief areas 134, although a single relief area 134 as well as morethan two relief areas 134 are also contemplated. The at least one reliefarea 134 may extend from a position on the undersurface 132 of the topmember 130 to at least one lateral side of the top member 130. Therelief areas 134 may be substantially planar and may be aligned with theholes 118 in the base member 110. The relief areas 134 are relativelyrectangular with the long axis of the rectangle extending along thelateral axis of the top member 130 or perpendicular to the longitudinalaxis of the device 100.

As seen in FIGS. 4-6, the relief areas 134 may be configured to matewith at least one correspondingly shaped load head 170 of the anexpansion mechanism 140. The top member 130 may also include at leastone hinge channel 136 and at least one pivot cylinder 138 and the hingechannels 136 may alternate with the pivot cylinders 138, as depicted inFIG. 6. The at least one hinge channel 136 of the top member 130 maymate with the at least one pivot cylinder 124 of the base member 110 andthe at least one pivot cylinder 138 of the top member 130 may mate withthe at least one hinge channel 126 of the base member 110 to enable theimplant 100 to extend on a first lateral side 106 while remaining closedon a second lateral side 108. A pin 139 may be inserted into openings125, 137 in the pivot cylinders 124, 138, respectively, to pivotallysecure the top member 130 to the base member 110. The pivot cylinders124 and hinge channels 126 of the base member 110 and the hinge channels136 and pivot cylinders 138 of the top member 130 allow the hingechannels 126, 136 to pivot or rotate around the outer diameter of thepivot cylinders 124, 138 when the at least one expansion assembly 142 isextended or retracted causing the top member 130 to tilt or slantrelative to the base member 130. In another embodiment, the base member110 may include a pivot cylinder 124 and the top member 130 may includea hinge channel 136, alternatively, the base member 110 may include ahinge channel 126 and the top member 130 may include a pivot cylinder138.

Referring now to FIG. 4 with continued reference to FIGS. 5 and 6, anexploded view of all of the components that comprise the implant 100 isshown. As shown in FIG. 7, the expansion mechanism 140 of the implant100 includes at least one expansion assembly 142 and a drive rod 180. Inone embodiment, as shown in FIG. 7, the expansion mechanism 140 includestwo expansion assemblies 142. The expansion assemblies 142 may include acylindrical gear 150, a support means 158, a threaded rod 160, and aload head 170. The vertical cylinder or cylindrical gears 150 (thesenames may be used interchangeably) may nest or be suspended within theholes 118 of the base member 110. The cylindrical gears 150 may includeexternal substantially vertical depressions or circumferential serialdepressions 152 positioned on the outer surface of the gears 150 whichextend around the entire circumference. For example purposes, the gears150 may have a smooth surface, above and below the substantiallyvertical depressions 152. Positioning the circumferential serialdepressions 152 around the central portion of the gears 150 may maximizestrength and improve trackability when the cylindrical gears 150 engagethe drive rod 180. The circumferential serial depressions 152 may alsoinclude uniquely oriented thread patterns. In addition, the gears 150may include internal threads 154 on the interior surface of the gears150.

As shown in FIG. 8, the support means 158 may sit on the shoulders 120of the base member 110 and function to maintain the expansion assemblies142 in a vertical orientation relative to the base member 110 andaligned with the holes 118. The support means 158 may also be usedadjacent to the gears 150 and threaded rods 160 and may hold the gears150 in the holes 118. The support means may, for example, be in the formof a ring, snap ring, washer or other similar type of structure thatwill secure the expansion assemblies 142 to the base member 110. Theshoulders 120 may also operate as bearing surfaces against which thesupport means 158 contacts to facilitate the rotation of the expansionassemblies 142 when actuated.

As shown in FIGS. 4, 7 and 8, the threaded rods 160 may include a pivotcylinder 162 located on the top or superior end of the threaded rods160. The terms “pivot cylinder,” “arcuate surface” and “curved surface”may be used interchangeably herein as they all refer to the samestructure of the threaded rods. The threaded rods 160 may also includeexternal threads 164 extending along its length. The external threads164 may be configured to match the internal threads 154 of the gears150. The pivot cylinder 162 of the threaded rods 160 may be insertedinto a distal channel 172 of the load heads 170. These constructs allowthe load heads 170 to pivot, slide, or rotate around the outer diameterof the pivot cylinders 162 when the threaded rods 160 are extendedcausing the top member 130 to tilt or slant. Tilted or slanted loadheads 170 are shown in FIGS. 3 and 8. The load heads 170 may alsoinclude superior head surfaces 174. The superior head surfaces 174 maybe shaped to match with the corresponding relief areas 134 on theundersurface 132 of the top member 130. The superior head surfaces 174are configured to slide within the reliefs 134 of the undersurface 132,if necessary, to allow for the expansion assemblies 142 to lengthen tocreate the angled relationship of the top member 130 relative to thebase member 110. The reliefs 134 in the undersurface 132 and thecorrespondingly shaped load heads 170 facilitate the angulation processand the load transfer between the top member 130 and the base member 110while avoiding potential binding of the expansion assemblies 142 duringthe expansion and retraction process.

The drive rod 180 of the expansion mechanism 140 may be inserted intothe adjustment opening 116 and sit in the channel 122 of the base member110, as shown in FIGS. 4, 7, and 8. The drive rod 180 may include of afirst worm gear 182, a second worm gear 184 and a cylindrical shaft 186.The first worm gear 182 and the second worm gear 184 may also have toolopenings 188 at a second end opposite the first end with the cylindricalshaft 186 for coupling with a tool 200. The tool opening 188 of thesecond worm gear 184 may mate with a corresponding protrusion on thefirst end of the first worm gears 182 to facilitate simultaneousrotation of both worm gears 182, 184. In another embodiment, the driverod 180 may include a single worm gear and a cylindrical shaft 186, thesingle worm gear would have a length to enable engagement with bothgears 150 simultaneously. In addition, the cylindrical shaft 186 mayinclude an opening 176 for mating with a pin 190 to secure the drive rod180 in the base member 110 to enable adjustment of the top member 130without the drive rod 180 moving out of the implant 100. The pin 190 mayalso prevent the drive rod 180 from advancing out of the implant 100after implantation into the patient's spine. By off-centering theadjustment opening 116 and the channel 122 from the longitudinal axis ofthe device 100, the worm gears 182, 184 of the drive rod 180, which areinserted into the channel 122, intersect with the holes 118 of the basemember 110. The worm gears 182, 184 may be configured to engage with thegears 150 of the expansion assemblies 142 which sit in the holes 118 ofthe base member 110. FIG. 8 shows the assembled implant 100 without thetop member 130 with the drive rod 180 positioned and extending throughthe length of the base member 110.

When the implant 100 is inserted into a patient using tool 200, as shownin FIGS. 12-14, the tool 200 engages the alignment opening 112, theattachment opening 114 and the adjustment opening 116, as described ingreater detail below. Once the tool 200 is inserted into the patientbetween two vertebrae, the drive rod 180 with the gears 150 function tomirror the rotational movement exerted by the tool 200, described ingreater detail below, and translate the movement to the gears 150. Theexpansion mechanism 140 functions to convert rotation movement of thegears 150 into linear or translational movement of the load heads 170positioned at the superior end of the threaded rods 160. Rotation of thegears 150 will result in a travel distance of the threaded rods 160 whenthe expansion mechanism 140 is actuated by the tool 200. As the gears150 are coupled to the drive rod 180, the coupled gears 150 will turn asthe drive rod 180 is rotated, thus avoiding the need for the tool 200 topass through the entire length of the channel 122 to engage the gear 150on the far end of the implant 100. Specifically, the second worm gear184 is coupled to the drive rod 180 on the far end of the implant 100and the first worm gear 182 is coupled to the drive rod 180 on the nearend of the implant 100.

With continued reference to FIGS. 1-11, as the drive rod 180 is rotatedby the tool 200 the teeth 178 of the worm gears 182, 184 of the driverod 180 are configured to mate with the substantially verticaldepressions 152 of the gears 150. As described above, the expansionassemblies 142 act to covert rotational movement of the gears 150 intotranslational movement of the threaded rods 160. This is achieved byallowing free rotational movement of the gears 150 while restricting therotation of the threaded rods 160. By restricting the rotation of thethreaded rods 160, the rods translate in either an upward or downwarddirection relative to the gears 150 depending upon whether the threads(external and internal) 154, 164 are oriented in a right-handed orleft-handed direction. As discussed above, when the threaded rods 160move, the load heads 170 contact the relief areas 134 of theundersurface 130 of the top member 130 to either move it away from ortowards the base member 110. In other words, the height of the implant100 either increases or decreases or the bone contacting surface 104will be angled relative to the base member 110 depending on therotational direction of the tool 200.

Referring now to FIGS. 9-11, a locking mechanism 192 for an embodimentof the adjustable interbody fusion device 100 is shown. As shown in FIG.10, the locking mechanism 192 may include a shaft 194 extending out froma head 196. The head 196 may include a plurality of protrusions 198 forengaging the lip 129 in the adjustment opening 116 of the base member110 to secure the locking mechanism 192 in the base member 110. The head196 may also include an opening 199 for engaging the insertion tool 200or a similar tool. The shaft 194 of the locking mechanism 192 may have ashape which corresponds to the shape of the tool openings 188 in theworm gears 182, 184 of the drive rod 180, for example, the shape may bea hexagon, square, or other multi-lobed configuration allowing the shaft194 of the locking mechanism 192 to fit securely within the openings 186of the drive rod 180. The shaft 194 of the locking mechanism 192 may beinserted, for example, through the opening 186 of the first worm gear182 and into the opening 186 in the second worm gear 184. Alternatively,the shaft 194 of the locking mechanism 192 may be inserted, for example,into the opening 186 of the first worm gear 182 to lock both the firstand second worm gears 182, 184 in the selected position where the firstworm gear 182 includes a protrusion on the first end that engages theopening 186 in the second worm gear 184. Similarly, the head 196 mayhave a shape which corresponds to the shape of the adjustment opening116, for example, the shape may be a circle, hexagon, square, or othermulti-lobed configuration allowing the locking mechanism 192 to securelyfit within the adjustment opening 116 of the base member 110 to securethe locking mechanism 192 in the implant 100 to maintain a desiredexpansion or retraction. Other shapes for the shaft 194 and the head 196of the locking mechanism 192 are also contemplated. The lockingmechanism 192 may be, for example, made of a rigid material or adeformable material. If the locking mechanism 192 is made of adeformable material it may be made slightly larger than the opening 186in the drive rod 180 and/or the adjustment opening 116 in the basemember 110, such that once it is inserted the larger size locks thedrive rod 180 in the desired position.

Referring now to FIGS. 12-14, one embodiment expansion tool 200 designedto engage and insert the implant 100 into a patient is shown. The tool200 is designed to engage the expansion mechanism 140. The insertion end202 of the tool 200 may be configured with a housing 204 including aprotrusion 206 shaped to correspond to the alignment opening 112 in thebase member 110. The insertion end 202 may also include an adjustmentmechanism 208 and a securement mechanism 210 which protrude out of thedistal end of the housing 204. The adjustment mechanism 208 may beconfigured, for example, to have a hex male head, square, or othermulti-lobed configuration that will allow for the user to rotate theknob 224 of the tool 200 and cause the expansion mechanism 140 torotate. Opposite the insertion end 202, the tool 200 has a handle 212which may be connected to the housing 204 by an attachment member 214.The attachment member 214 may be coupled to the housing 204 on theproximal end and secured to the handle 212 by fasteners 248, forexample, screws, pins, rivets, and the like. The tube 214 may house theadjustment mechanism 208 and the securement mechanism 210 which mayextend from the handle 212 to the insertion end 202 inside the housing204.

As seen in FIG. 13, the handle 212 of the tool 200 may also include afirst opening 216 along the longitudinal axis of the handle 212. Inaddition, the handle 212 of tool 200 may include a second opening 218extending perpendicular to and engaging the first opening 216. Thehandle 212 may also include a first knob 220 which may be inserted intothe first opening 216 at a proximal end of the handle 212 to engage theadjustment mechanism 208. An actuation bar 226 may be inserted into thesecond opening 218. A gear 228 may be inserted into the first opening216 prior to inserting the first knob 220 enabling the gear 228 toengage the first knob 220 as it is inserted into the handle 212 toengage the adjustment mechanism 208. The knob 220 may include a head 236with a shaft 238 extending out away from the inferior surface of thehead 236. The shaft 238 of the knob 220 may also include an opening formating with the adjustment mechanism 208 to secure the knob 220 to theadjustment mechanism 208.

A second knob 222 may couple to the proximal end of the handle 212 overthe opening 216 and the gear 228. The gear 228 may include teeth on theexterior surface which engage corresponding grooves on the interiorsurface of the second knob 222. The second knob 222 may be rotatablysecured to the handle 212 by an end plate 252 which may be attached tothe handle 212 using fasteners 248, for example, screws. A third knob224 may couple to the proximal end of the housing 204 at the distal endof the handle 212. The third knob 224 may also engage a gear 250 whichaligns with a channel in the attachment means 214 of the housing 204.The gear 250 may include grooves circumferentially around the exteriorsurface that mate with corresponding grooves circumferentially aroundthe interior surface of the third knob 224.

As seen in FIGS. 12 and 13, the adjustment mechanism 208 may pass intothe first opening 216 from the proximal end of the handle 212. Theadjustment mechanism 208 may be secured to the distal end of the shaft238 of the knob 220 prior to insertion into the first opening 216 fromthe proximal end of the handle 212. A tool engagement end 242 of theadjustment mechanism 208 couples with the distal end of the shaft 238 toenable rotation of the adjustment mechanism 208. The tool engagement end242 of the adjustment mechanism 208 when inserted into the first opening216 passes through a hole 230 in the actuation bar 226 before engagingthe shaft 238 of the knob 220. The adjustment mechanism 208 may includea first channel 232, a second channel 234, and a third channel 240 forengaging the hole 230 in the actuation bar 226 to secure the adjustmentmechanism 208 at a desired length at the insertion end 202. Thesecurement mechanism 210 may pass into the second opening 218 from thedistal end of the handle 212 enabling engagement with the distal end ofthe shaft 238 of the knob 220 when inserted into the second opening 218from the proximal end of the handle 212. In addition, the securementmechanism 210 may include a spring mechanism 246 inserted over theproximal end of the securement mechanism 210 to spring load thesecurement mechanism 210. The spring mechanism 246 may also engage anend member 250 in the handle 212 which may provide a bearing surface forthe spring mechanism 246 to engage. A tool engagement end 244 of thesecurement mechanism 210 couples with a gear 250 which engages theinterior surface of the third knob 224 to enable rotation of thesecurement mechanism 210. The tool engagement ends 242, 244 may have,for example, a hex male head, square, or other multi-lobed configurationto enable rotation of the adjustment mechanism 208 or securementmechanism 210, respectively.

During use, the tool 200 may be inserted into the implant 100 byaligning the protrusion 206 of the insertion end 202 of the tool 200with the alignment opening 112 of the implant 100. The third knob 224may then be rotated thereby rotating the gear 250 and the engagedsecurement mechanism 210. As the knob 224 is rotated the threaded end ofthe securement mechanism 210 engages the threads in the tool attachmentopening 114 of the implant 100 to secure the implant 100 to the tool 200for insertion into a patient. In addition, as the securement mechanism210 engages the attachment opening 114 of the implant 100, theadjustment mechanism 208 of the tool will engage the opening 186 in thedrive rod 180 of the implant 100.

Once the tool 200 and implant 100 are aligned and the shaft 238 of theknob 220 is coupled to the tool engagement end 242 of the adjustmentmechanism 208, the adjustment mechanism 208 may be inserted into thefirst opening 216. As the adjustment mechanism 208 is inserted into thehandle 212, the actuation bar 226 is depressed allowing for theadjustment mechanism 208 to pass through the hole 230 in the actuationbar 226. The adjustment mechanism 208 passes through the handle 212 andthe housing 204 and extends out of the insertion end 202 to pass throughthe adjustment opening 116 of the implant 100 and engage the expansionmechanism 140. Once the adjustment mechanism 208 engages the expansionmechanism 140 the actuation bar 226 may be released to engage one of thechannels 232, 234, 240 of the adjustment mechanism 208 and maintain theposition of the adjustment mechanism 208 at a desired length.

After the actuation bar 226 of the handle 212 has engaged a channel 232,234, 240, the implant 100 may then be inserted into the desired positionin the patient. The head 236 of the knob 220 may then be rotated whichin turn will rotate the distal end of the adjustment mechanism 208. Asthe head 236 of the knob 220 is rotated, the adjustment mechanism 208,which is coupled to the opening 186 in the drive rod 180, engages theexpansion mechanism 140 and expands a side of the implant 100 to anglethe top member 130 relative to the base member 110. The cogs or teeth178 of the worm gears 182, 184 of the drive rod 180 are sized to matewith the corresponding serial depressions 152 of the gears 150 tofacilitate rotation of the gears 150 when the knob 220 of the tool 200is turned. Alternatively, the second knob 222 may be used to rotate theadjustment mechanism 208 to facilitate rotation of the gears 150 toexpand a side of the implant 100. The first knob 220 enables slowerrotation of the adjustment mechanism 208, while the second knob 222enables faster rotation of the adjustment mechanism 208 enabling fasteropening or closing of the implant 100. Once the desired expansion of theimplant 100 is achieved, the tool 200 may then be removed from thepatient.

In the embodiment shown in FIGS. 12-14, prior to removing the tool 200,the locking mechanism 192 may be inserted into the implant 100 to securethe top member 130 of the implant 100 in the desired expansion and/orretraction relative to the base member 110. The locking mechanism 192may be inserted into the opening 186 in the drive rod 180 by removingthe adjustment mechanism 208 and first knob 220 from the tool 200 bydepressing the actuation bar 226 and pulling the knob 220 out of theopening 216. Once the adjustment mechanism 208 has been removed alocking tool, not shown, with a locking mechanism 192 coupled to aninsertion end of the locking tool may be inserted into the opening 216through the handle 212 and the housing 204 existing the insertion end202 to engage the implant 100.

As the locking mechanism 192 is inserted into the base member 110 andthe drive rod 180, the shaft 194 of the locking mechanism 192 fitssecurely within the opening 186 of the drive rod 180. In one embodiment,the shaft 194 may extend through the opening 186 in the first worm gear182 and into the opening 186 in the second worm gear 184. Alternatively,in another embodiment, a shorter shaft 194 may extend into the opening186 in the first worm gear 182 and the first and second worm gears 182,184 may be coupled such that the locking mechanism 192 inserted into thefirst worm gear 182 secures both the worm gears 182, 184 in the desiredposition. In addition, the plurality of protrusions 198 on the head 196may engage the lip 129 in the adjustment opening 116 of the base member110, as shown in FIGS. 9-11. The drive rod 180 may be recessed withinthe base member 110 to provide a cavity for insertion of the lockingmechanism 192 into the base member 110, such that when the lockingmechanism 192 is inserted into the base member 110 of the implant 100 itis flush with the exterior surface of the base member 110.

The tool 200 may be removed from the patient by removing the adjustmentmechanism 208 or the locking insert mechanism. The adjustment mechanism208 or the locking insert mechanism may be removed from the firstopening 216 by depressing the actuation bar 226 to disengage theactuation bar 226 from the channel 232, 234, 240 or a channel in thelocking insert mechanism, not shown. Once the actuation bar 226 isdisengaged the adjustment mechanism 208 or the locking insert mechanismmay be removed from the first opening 216. Next, the securementmechanism 210 may be disengaged from the implant 100 by rotating thethird knob 224 which in turn rotates the securement mechanism 210. Asthe securement mechanism 210 rotates it disengages the threads 108 ofthe attachment opening 114 and the protrusion 206 of the insertion end202 of the tool 200 slide out of the alignment opening 112. It is alsocontemplated that the above method for inserting the implant 100 usingtool 200 may be performed in alternative orders.

As depicted in FIGS. 15-17, the general arrangement of an adjustableinterbody fusion device 300, in one embodiment, includes a base member310, at least one moveable top member 330, and at least one expansionmechanism 340. The device 300 as seen in FIG. 15 may have, for example,a generally rectangular geometry with various configured long sides tofacilitate insertion and bone coverage. Although it would be understoodby one skilled in the art that other outside configurations, includingsquare-like shapes, can be used. The top member 330 may be detachablycoupled to the body member 310.

As seen in FIGS. 15 and 16, base member 310 may have at least onethrough hole or central opening 302 for insertion of bone graft materialdisposed on the inferior and superior bone contacting surfaces 304. Theopening 302 typically extends through both bone contacting surfaces 304of the base and top members 310, 330 and into the inner cavity of theassembled device 300. The size and configuration of the opening 302allow bone graft material to be inserted inside the implant 300 toachieve a continuous fusion between the inferior and superior vertebralbodies.

As shown in FIG. 15, the superior and inferior bone contacting surfaces304 may be generally parallel to each other. However, the expansionmechanisms or movement mechanisms 340 (these names may be usedinterchangeably) allow the user to angle one side of the bone contactingsurface 304 of the top member 330 relative to the bone contactingsurface 304 of the base member 310 as seen in FIGS. 16 and 17, whereinthe near side is fully expanded and the far side remains retracted. Asshown in FIGS. 15-18 the bone contacting surfaces 304 are of the typedescribed above with reference to the bone contacting surfaces 104 ofimplant 100 and for brevity sake will not be described again here.

As seen in FIGS. 18 and 19, the base member 310 may also include a toolalignment opening 312 on a first lateral side of the base member 310, atool attachment opening 314 in the tool alignment opening 312, and afirst adjustment opening 316 and second adjustment opening 317 on thelateral side of the base member 310 and which may be on opposite sidesof the tool alignment opening 312, as seen in FIGS. 15-19. The basemember 310 may also include at least one hole or lumen 318 near theproximal and/or distal ends of the base member 310 to house at least oneexpansion mechanism 340, which will be discussed in greater detailbelow. In one embodiment, as illustrated in FIGS. 15-23, the base member310 may include, for example, two holes 318. The holes 318 may be of thetype described above with reference to holes 118 of implant 100 and forbrevity sake will not be described again here. The base member 310 mayalso include at least one pivot cylinder 324, at least one hinge channel326, and at least one opening 328. The at least one pivot cylinder 324and the at least one hinge channel 326 may alternate as depicted inFIGS. 18 and 19.

As seen in FIGS. 18 and 20, the top or superior member 330 also includesan undersurface 332 with at least one relief area 334 that is adjacentto the central opening 302. The central opening 302 may be configured topermit the insertion of bone graft material into the inner cavity of theimplant 300 prior to or after implantation. In one embodiment, asillustrated in FIGS. 15-23, the top member 330 may include, for example,two relief areas 334 which may be of the type described above withreference to relief areas 134 and for brevity sake will not be describedagain here.

As seen in FIGS. 18-20, the relief areas 334 may be configured to matewith at least one correspondingly shaped load head 370 of the anexpansion mechanisms 340. The top member 330 may also include at leastone hinge channel 336 and at least one pivot cylinder 338 and the hingechannels 336 may alternate with the pivot cylinders 338, as depicted inFIG. 20. The at least one hinge channel 336 may mate with the at leastone pivot cylinder 324 of the base member 310 and the at least one pivotcylinder 338 may mate with the at least one hinge channel 326 of thebase member 310 to enable the implant 300 to extend on a first lateralside 306 while remaining closed on a second lateral side 308. A pin 339may be inserted into openings 325, 337 in the pivot cylinders 324, 338,respectively, to pivotally secure the top member 330 to the base member310. The pivot cylinders 324 and hinge channels 326 of the base member310 and the hinge channels 336 and pivot cylinders 338 of the top member330 allow the hinge channels 326, 336 to pivot or rotate around theouter diameter of the pivot cylinders 324, 338 when the at least oneexpansion assembly 342 is extended or retracted causing the top member330 to tilt or slant relative to the base member 330. In anotherembodiment, the base member 310 may include a pivot cylinder 324 and thetop member 330 may include a hinge channel 336, alternatively, the basemember 310 may include a hinge channel 326 and the top member 330 mayinclude a pivot cylinder 338.

Referring now to FIG. 18 with continued reference to FIGS. 19 and 20, anexploded view of all of the components that comprise the implant 300 isshown. As shown in FIG. 21, the two expansion mechanisms 340 of theimplant 300 include an expansion assembly 342 and a drive rod 380. Theexpansion assemblies 342 may include a cylindrical gear 350, a supportmeans 358, a threaded rod 360, and a load head 370. The verticalcylinder or cylindrical gears 350 may be of the type described abovewith reference to cylindrical gears 150 of implant 100 and for brevitysake will not be described again here.

As shown in FIG. 22, the support means 358 may sit on the shoulders 320of the base member 310 and function to maintain the expansion assemblies342 in a vertical orientation relative to the base member 310 andaligned with the holes 318. The support means 358 may also be usedadjacent to the gears 350 and threaded rods 360 and may hold the gears350 in the holes 318. The support means 358 may be of the type describedabove with reference to support means 158 of implant 100 and for brevitysake will not be described again here. The shoulders 320 may alsooperate as bearing surfaces against which the support means 358 contactsto facilitate the rotation of the expansion assemblies 342 whenactuated.

As shown in FIGS. 18, 21 and 22, the threaded rods 360 may be of thetype described above with reference to the threaded rods 160 of theimplant 100 and for brevity sake will not be described again here. Thepivot cylinder 362 of the threaded rods 360 may be inserted into adistal channel 372 of the load heads 370. These constructs allow theload heads 370 to pivot, slide, or rotate around the outer diameter ofthe pivot cylinders 362 when the threaded rods 360 are extended causingthe top member 330 to tilt or slant. Tilted or slanted load heads 370are shown in FIGS. 17 and 22. The load heads 370 may be of the typedescribed above with reference to load heads 170 of the implant 100 andfor brevity sake will not be described again here. The reliefs 334 inthe undersurface 332 and the correspondingly shaped load heads 370facilitate the angulation process and the load transfer between the topmember 330 and the base member 310 while avoiding potential binding ofthe expansion assemblies 342 during the expansion and retractionprocess.

The drive rods 380 of the expansion mechanisms 340 may be inserted intothe adjustment openings 316 and sit in the channel 322 of the basemember 310, as shown in FIGS. 18, 21, and 22. Each drive rod 380 mayinclude a worm gear 382 and a cylindrical shaft 386. The worm gear 382may also have a tool opening 388 in an end of the cylindrical shafts 386for coupling with a tool 400. In addition, the cylindrical shafts 386may include a channel 376 for mating with a pin 390 to secure the driverods 380 in the base member 310 to enable adjustment of the top member330 without the drive rod 380 backing out of the implant 300. The pin390 may also prevent the drive rod 380 from backing out of the implant300 after implantation into the patient's spine (See FIG. 23). Byplacing the adjustment openings 316 and the channels 322 in a side ofthe implant 300, the worm gears 382 of the drive rods 380, which areinserted into the channels 322, intersect with the holes 318 of the basemember 310. The worm gears 382 may be configured to engage with thegears 350 of the expansion assemblies 342 which sit in the holes 318 ofthe base member 310. FIG. 22 shows the assembled implant 300 without thetop member 330 with the drive rods 380 positioned offset from thelateral axis and extending laterally into the base member 310.

When the implant 300 is inserted into a patient using tool 400, as shownin FIG. 24, the tool 400 engages the alignment opening 312, theattachment opening 314 and the adjustment openings 316, as described ingreater detail below. Once the implant 300 is inserted into the patientbetween two vertebrae using the tool 400, the drive rods 380 with thegears 350 function to mirror the rotational movement exerted by the tool400, described in greater detail below, and translate the movement tothe gears 350. The expansion mechanisms 340 function to convert rotationmovement of the gears 350 into linear or translational movement of theload heads 370 positioned at the superior end of the threaded rods 360.Rotation of the gears 350 will result in a travel distance of thethreaded rods 360 when the expansion mechanisms 340 are actuated by thetool 400. As the gears 350 are coupled to the drive rods 380, thecoupled gears 350 will turn as the drive rod 380 is rotated.

With continued reference to FIGS. 15-23, as the drive rods 380 arerotated by the tool 400 the teeth 378 of the worm gears 382 of the driverods 380 are configured to mate with the substantially verticaldepressions 352 of the gears 350. As described above, the expansionassemblies 342 act to covert rotational movement of the gears 350 intotranslational movement of the threaded rods 360. This is achieved byallowing free rotational movement of the gears 350 while restricting therotation of the threaded rods 360. By restricting the rotation of thethreaded rods 360, the rods translate in either an upward or downwarddirection relative to the gears 350 depending upon whether the threads(external and internal) 354, 364 are oriented in a right-handed orleft-handed direction. As discussed above, when the threaded rods 360move, the load heads 370 contact the relief areas 334 of theundersurface 332 of the top member 330 to either move it away from ortowards the base member 310. In other words, the bone contacting surface304 of the top member 330 will be angled relative to the base member 310depending on the rotational direction of the tool 400. Lockingmechanisms, for example, the locking mechanism 192 of FIG. 10, whichwill not be described again here for brevity sake, may be inserted intoadjustment openings 316 to secure the implant 100 in the desiredexpansion or retraction.

Referring now to FIGS. 24-35, a tool 400 for inserting the implant 300into a patient is shown. The tool 400 is designed to engage theexpansion mechanisms 340. The insertion end 402 of the tool 400 may beconfigured with a housing 404 including a protrusion 406 shaped tocorrespond to the alignment opening 312 in the base member 310. Theinsertion end 402 may also include at least one adjustment mechanism 408and a securement mechanism 410 which protrude out of the distal end ofthe housing 404. The adjustment mechanisms 408 may be configured, forexample, to have a hex male head, square, or other multi-lobedconfiguration that will allow for the user to rotate the knob 424 of thetool 400 and cause the expansion mechanisms 340 to rotate. Thesecurement mechanism 410 may be configured, for example, to includethreads for engaging corresponding threads in the attachment opening314.

Opposite the insertion end 402, the tool 400 has a handle 412 which maybe connected to the housing 404 of the insertion end 402 by at least onetube 414. In one embodiment, there are three tubes 414, a center tube414 for the securement mechanism 410 and two lateral tubes 414 for theadjustment mechanisms 408. The at least one tube 414 may be coupled tothe housing 404 on the distal end and secured to an attachment member420 which couples to the handle 412 at the proximal end by fasteners,for example, screws. The securement mechanism 410 may extend from thehandle 412 to the housing 404 inside the center tube 414. In addition,the adjustment mechanisms 408 may also extend between the housing 404and the handle 412 inside the tubes 414 adjacent to the center tube 414with the securement mechanism 410.

As seen in FIGS. 27-29, the handle 412 of the tool 400 may also includea first opening 416 along the longitudinal axis of the handle 412 and asecond opening 418 extending into the handle 412 from the distal end.The handle 412 may also include a first knob 422 and a second knob 424.The first knob 422 may engage the securement mechanism 410 at a proximalend and the distal end of the securement mechanism 410 may be insertedinto the opening 416 in the handle 412. The second knob 424 may engagean attachment member 420 which in turn may be inserted into a portion ofthe handle 412 through opening 418. The attachment member 420 mayinclude two grooves 432, 434, each groove 432, 434 mates with two gears450 and two spring mechanisms 446. The gears 450 may fit into thegrooves 432, 434 and a spring 446 may sit on the proximal end of thegears 450, the knob 424 may fit over the springs 446 and gears 450 tocouple the exterior grooves of the gears 450 with the interior groovesof the knob 424. The attachment member 420 may then be inserted into thehandle 412 and secured. The adjustment mechanisms 408 may engage thedistal end of the gears 450 to enable rotation of the adjustmentmechanisms 408 by rotating the knob 424.

During use a surgeon may insert the tool 400 into the implant 300 byaligning the protrusion 406 of the insertion end 402 of the tool 400with the alignment opening 312 of the implant 300. Once the tool 400 andimplant 300 are aligned, the securement mechanism 410 may be coupled ata proximal end to the knob 422. The securement mechanism 410 may then beinserted into the opening 416. The securement mechanism 410 may beadvanced through the handle 412, the attachment member 420, and the tube414 until the distal end of the securement mechanism 410 extends out ofthe housing 404. The knob 422 of the tool 400 may be rotated which inturn will rotate the securement mechanism 410. As the knob 422 rotatesthe securement mechanism 410, the distal end of the securement mechanism210 engages the threads 308 of the attachment opening 314 of the implant300. The securement mechanism 410 of the tool will couple with theattachment opening 314 of the implant 300 to secure the implant 300 tothe tool 400 for insertion into a patient. In addition, as thesecurement mechanism 410 engages the attachment opening 314 of theimplant 300, the adjustment mechanisms 408 of the tool will engage theopenings 386 in the drive rods 380 of the implant 300.

Once the implant 300 is secured to the tool 400, the implant 300 maythen be inserted into the desired position in the patient. The physicianmay then rotate the knob 424 which in turn will rotate the distal endsof the adjustment mechanisms 208. As the knob 424 is rotated, theadjustment mechanisms 408, which are coupled to the openings 386 in thedrive rods 380, engages the expansion mechanisms 340 and expands thenear side of the implant 300 to angle the top member 330 relative to thebase member 310. The cogs or teeth 378 of the worm gears 384 on the endof the drive rods 380 are sized to mate with the corresponding serialdepressions 352 of the gears 350 to facilitate rotation of the gears 350when the knob 424 of the tool 400 is turned. Once the desired expansionof the implant 300 is achieved, the tool 400 may then be removed fromthe patient.

The tool 400 may be removed from the patient by rotating the knob 422 todisengage the distal end of the securement mechanism 410 from theattachment opening 314 of the implant 300. As the securement mechanism410 rotates it disengages the attachment opening 314 and the protrusion406 and the adjustment mechanisms 408 of the insertion end 402 of thetool 400 may slide out of the alignment opening 412 and adjustmentopenings 416, respectively. After the tool 400 is removed from theimplant 300, locking mechanisms, for example, locking mechanism 192 asshown in FIG. 10 may be inserted into the openings 316 to lock theimplant 300 in the desired expansion or retraction. It is alsocontemplated that the above method for inserting the implant 300 usingtool 400 may be performed in alternative orders.

Referring now to FIGS. 36-38, an adjustable interbody fusion device 500,is shown and includes a base member 510, at least one moveable topmember 530, and at least one expansion mechanism 540. The device 500 isof the type described in U.S. application No. Ser. No. 61/756,048 filedJan. 24, 2013, which is herein incorporated by reference in itsentirety. An alternative embodiment hinge mechanism 506 including atleast one pivot cylinder 524 and at least one hinge channel 536 is shownin FIGS. 36-38. As shown, the hinge mechanism 506 includes at least onepivot cylinder 524 and at least one hinge channel 536 in the base member510 and at least one pivot cylinder 524 and at least one hinge channel536 in the top member 530. The at least one hinge channel 536 of the topmember 530 may mate with the at least one pivot cylinder 524 of the basemember 510 and the at least one pivot cylinder 524 of the top member 530may mate with the at least one hinge channel 536 of the base member 510to enable the implant 500 to extend on a far end while remaining closedon a near end. A pin 539 may be inserted into openings 525 in the pivotcylinders 524, to pivotally secure the top member 530 to the base member510. The pivot cylinders 524 and hinge channels 536 of the base member510 and the hinge channels 536 and pivot cylinders 524 of the top member530 allow the hinge channels 536 to pivot or rotate around the outerdiameter of the pivot cylinders 524 when the at least one expansionassembly 542 is extended or retracted causing the top member 530 to tiltor slant relative to the base member 530. The expansion mechanism 540 ofthe implant 500 includes at least one expansion assembly 542 and a driverod 580. The expansion assembly 542 may include a cylindrical gear 550,a support means 558, a threaded rod 560, and a load head 570. Thecylindrical gear 550, support means 558, threaded rod 560, and load head570 are of the type described above with reference to implants 100 and300. A locking mechanism 192, of the type described above with referenceto FIG. 10, may be inserted into opening in the drive rod 580 to securethe expansion assembly 542 in place to maintain a desired expansion orretraction of the implant 500.

Referring now to FIGS. 39-41, an adjustable interbody fusion device 600,is shown and includes a base member 610, at least one moveable topmember 630, and an expansion mechanism 640. The base member 610 may beof the type described above with reference to base member 110 which willnot be described again here for brevity sake. As shown in FIG. 39, theexpansion mechanism or movement mechanism 640 allows a user to angle orraise one side of the bone contacting surface 104 of the top member 630relative to the bone contacting surface 104 of the base member 610,wherein the near side is expanded and the far side remains engaged orhinged. The bone contacting surfaces 104 of the device 600 are the sameas the bone contacting surfaces 104 as described above with reference todevice 100, which will not be described again here for brevity sake.

The top or superior member 630, as shown in FIGS. 39-41, may be similarto the top member 130 as described in greater detail above and only thechanged features will be described here for brevity sake. The top member630 may include at least one relief area 134 on the undersurface 132 ofthe top member 630, as described above with reference to FIGS. 4 and 6.In the depicted embodiment there are two relief areas 134, although onerelief area 134 and more than two relief areas 134 are alsocontemplated. The relief areas 134 may extend from an intermediateposition on the undersurface 132 of the top member 630 to at least oneouter side of the top member 630. As shown in FIGS. 39-41, the at leastone relief area 134 may also include at least one stop pin 634. The stoppin 634 may be positioned closer to the first lateral side 106 than tothe second lateral side 108 of the relief area 134 on the undersurface132 of the top member 630. The stop pin 634 may be an integral portionof the top member 630 or alternatively, the stop pin 634 may beremovable. If a removable stop pin 634 is used the relief areas 134 mayeach include an opening (not shown) for receiving the stop pin 634. Aremovable stop pin 634 may be secured into the opening (not shown) onthe undersurface 132 of the top member 630 by, for example, threads, anadhesive, press-fitting, and the like. The stop pin 634 may protrude orextend out from a surface of the relief area 134 to engage a load head670, which will be described in greater detail below, and prevent itfrom sliding out of the relief area 134.

The expansion mechanism 640 of the implant 600, as shown in FIG. 40, mayinclude at least one expansion assembly 642 and a drive rod 180. Theexpansion assemblies 642 may include a cylindrical gear 150, a supportmeans 158, a threaded rod 160, and a load head 670. The cylindrical gear150, support means 158, and threaded rod 160 may be of the typedescribed above with reference to device 100 and will not be describedagain here for brevity sake. The load head 670 may be similar to loadhead 170 as described above with reference to device 100. The load head670 may include a distal channel 672 which may receive the pivotcylinder 162 of the threaded rods 160. The load heads 670 may alsoinclude superior head surfaces 674 that may be shaped to mate with thecorresponding relief areas 134 on the undersurface 132 of the top member630. The superior head surfaces 674 may also include a cutout 676 shapedto receive the stop pins 634. When the load heads 670 are positioned inthe relief areas 134, the cutout 676 may be positioned toward the firstlateral side 106 of the top member 630. The superior head surfaces 674are configured to slide within the reliefs 134 of the undersurface 132,if necessary, to allow the expansion assemblies 642 to lengthen tocreate the angled relationship of the top member 630 relative to thebase member 610. The stop pins 634 are positioned in the relief areas134 to engage the cutouts 676 in the load heads 670 to prevent the loadheads 670 from sliding out of the relief areas 134 while the top member630 is expanded or retracted relative to the base member 610. Thecutouts 676 may have, for example, a relatively circular shape tocorrespond to the circular shape of the stop pins 634, althoughalternative shapes for the cutouts 676 and stop pins 634 are alsocontemplated.

The drive rod 180 of the expansion mechanism 140, as shown in FIG. 40,may include at least one worm gear 682 and a cylindrical shaft 186. Thecylindrical shaft 186 may be of the type described above with referenceto device 100 and which will not be described again here for brevitysake. The at least one worm gear 682 may be similar to the worm gears182 and 184 as described above with reference to device 100 and only thedifferences will be described here for brevity sake. The worm gear 682of device 600 will have a length essentially the same size as thecombined length of worm gears 182, 184. The length of the worm gear 682will enable engagement with both gears 150 of the expansion assemblies142 simultaneously. The worm gear 682 may be a monolithic rod thatextends along the length of the bottom member 610. In an alternativeembodiment, the drive rod 180 may be a monolithic rod extending alongthe length of the bottom member 610 in channel 122.

The stop pins 634 may also be used in the top members 130, 330 of thedevices 100, 300 shown in FIGS. 4 and 18. In addition, cutouts 676 maybe formed in the load heads 170, 370 of the devices 100, 300 to receivethe stop pins 634 of the top members 130, 330. Further, if the topmember 530 of device 500, as shown in FIG. 38, was altered such that therelief area of top member 530 extended all the way to the side of thedevice 500, then a stop pin 634 may be used in the top member 530 alongwith a cutout 676 in the load head 570 to prevent the load head 570 fromsliding out of the relief area of the top member 530 as the top member530 is tilted relative to the base member 510.

A surgical method for maintaining a space between two vertebral bodiesin a spine may include: obtaining a medical device 100, 300, 500, 600.The medical device 100, 300, 500, 600 including a body member 110, 310,510, 610 with at least one pivot cylinder 124, 324, 524 and at least onehinge channel 126, 326, 536, a moveable member 130, 330, 530, 630 withat least one pivot cylinder 138, 324, 524 and at least one hinge channel136, 326, 536, wherein the at least one pivot cylinder 124, 324, 524 ofthe body member 110, 310, 510, 610 engages the at least one hingechannel 136, 326, 536 of the moveable member 130, 330, 530, 630 and theat least one pivot cylinder 138, 324, 524 of the moveable member 130,330, 530, 630 engages the at least one hinge channel 126, 326, 536 ofthe body member 110, 310, 510, 610, and at least one movement mechanism140, 340, 542, 640 engaging the moveable member 130, 330, 530, 630 andthe body member. The method also including inserting and coupling a toolinto at least two openings within the medical device 100, 300, 500, 600,slidingly inserting the medical device 100, 300, 500, 600 into a spacebetween two vertebral bodies, and adjusting the tool to move a firstside of the moveable member 130, 330, 530, 630 in a vertical directionrelative to the body member 110, 310, 510, 610. Coupling the tool intoat least two openings within the medical device 100, 300, 500, 600 mayinclude securing the securement mechanism into the at least two openingsin the medical device 100, 300, 500, 600. Adjusting the tool to move thefirst side of the moveable member 130, 330, 530, 630 in a verticaldirection relative to the body member 110, 310, 510, 610 may includeturning the at least one second knob to actuate the at least onemovement mechanism 140, 340, 542, 640 to move the first side of themoveable member 130, 330, 530, 630 in a vertical direction relative tothe body member 110, 310, 510, 610.

The tool may include a handle, an insertion end, at least one tubeextending distally away from the handle and connecting the handle andthe insertion end, a securement mechanism coupled to the handle,extending through the at least one tube and protruding from theinsertion end, at least one adjustment mechanism coupled to the handle,extending through the at least one tube and protruding from theinsertion end, a first knob for actuating the securement mechanism, andat least one second knob for actuating the at least one adjustmentmechanism.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprise” (andany form of comprise, such as “comprises” and “comprising”), “have” (andany form of have, such as “has”, and “having”), “include” (and any formof include, such as “includes” and “including”), and “contain” (and anyform of contain, such as “contains” and “containing”) are open-endedlinking verbs. As a result, a method or device that “comprises,” “has,”“includes,” or “contains” one or more steps or elements possesses thoseone or more steps or elements, but is not limited to possessing onlythose one or more steps or elements. Likewise, a step of a method or anelement of a device that “comprises,” “has,” “includes,” or “contains”one or more features possesses those one or more features, but is notlimited to possessing only those one or more features. Furthermore, adevice or structure that is configured in a certain way is configured inat least that way, but may also be configured in ways that are notlisted.

Although the example embodiments have been depicted and described indetail herein, it will be apparent to those skilled in the relevant artthat various modifications, additions and substitutions can be madewithout departing from its essence and therefore these are to beconsidered to be within the scope of the following claims.

What is claimed is:
 1. An interbody fusion device, the devicecomprising: a base member including at least one of a pivot cylinder anda hinge channel; a top member including at least one of a pivot cylinderand a hinge channel corresponding to the pivot cylinder or hinge channelon the base member, wherein the at least one pivot cylinder or at leastone hinge channel of the base member engages the at least one hingechannel or at least one pivot cylinder of the top member; and at leastone movement mechanism engaging the top member and the base member, theat least one movement mechanism comprising: a first expansion assemblyhaving a first cylindrical gear, a first threaded rod, and a first loadhead, the first cylindrical gear comprising a plurality of depressionson an exterior surface of the first cylindrical gear and a plurality ofthreads on an interior surface, the first threaded rod comprising aplurality of threads on an exterior surface of the first threaded rodfor engaging the plurality of threads on the interior surface of thefirst cylindrical gear and a curved surface on a superior end, the loadhead comprising a channel positioned on a bottom surface of the loadhead for receiving the curved surface of the threaded rod.
 2. Theinterbody fusion device of claim 1, wherein the top member includes atleast one relief area adapted to receive a superior portion of the firstload head.
 3. The interbody fusion device of claim 2, wherein the atleast one relief area extends along an undersurface of the top memberand terminates at an opening on at least one lateral side of the topmember.
 4. The interbody fusion device of claim 3, wherein the at leastone relief area extends from an intermediate position on theundersurface of the top member to at least one outer side of the topmember, wherein the at least one relief area further comprises: at leastone stop pin extending out from a surface of the at least one reliefarea.
 5. The interbody fusion device of claim 4, wherein the at leastone movement mechanism comprises: a drive rod for engaging the pluralityof depressions.
 6. The interbody fusion device of claim 5, furthercomprising: a locking mechanism for engaging the drive rod to secure theat least one movement mechanism.
 7. The interbody fusion device of claim4, wherein the at least one movement mechanism comprises: a first driverod moveably coupled to the first expansion assembly; a second expansionassembly; and a second drive rod moveably coupled to the secondexpansion assembly.
 8. The interbody fusion device of claim 7, whereinthe first expansion assembly comprises: a first support means positionedwithin a shoulder of the base member to secure the first cylindricalgear in a first opening in the base member; and wherein the secondexpansion assembly comprises: a second cylindrical gear comprising aplurality of circumferential depressions on an exterior surface of thesecond gear for receiving the drive rod and a plurality of threads on aninterior surface; a second support means positioned within a shoulder ofthe base member to secure the second cylindrical gear in a secondopening in the base member; a second threaded rod comprising a pluralityof threads on an exterior surface of the second threaded rod forengaging the plurality of threads on the interior surface of the secondgear and a arcuate surface on a superior end; and a second load head. 9.The interbody fusion device of claim 8, wherein the first and secondload heads each comprise: a superior head surface on a top surface ofthe load heads for engaging a relief area on an undersurface of the topmember; and a cutout in the superior head surface.
 10. The interbodyfusion device of claim 1, wherein the at least one movement mechanismcomprises: a drive rod for engaging the plurality of depressions. 11.The interbody fusion device of claim 1, further comprising: a secondexpansion assembly, the drive rod rotatably connecting the firstexpansion assembly and the second expansion assembly.
 12. The interbodyfusion device of claim 11, wherein the first expansion assemblycomprises: a first support means positioned within a shoulder of thebase member to secure the first cylindrical gear in a first opening inthe base member; and wherein the second expansion assembly comprises: asecond cylindrical gear comprising a plurality of openings on anexterior surface of the second gear for engaging the drive rod and aplurality of threads on an interior surface; a second support meanspositioned within a shoulder of the base member to secure the secondcylindrical gear in a second opening in the base member; a secondthreaded rod comprising a plurality of threads on an exterior surface ofthe second threaded rod for engaging the plurality of threads on theinterior surface of the second gear and a curved surface on a superiorend; and a second load head.
 13. The interbody fusion device of claim12, wherein the first and second load heads each comprise: a superiorhead surface on a top surface of the load heads for engaging the reliefarea on the undersurface of the top member; and a cutout in the superiorhead surface.
 14. The interbody fusion device of claim 1, wherein thecurved surfaces comprises a pivot cylinder.
 15. The interbody fusiondevice of claim 1, wherein the at least one movement mechanismcomprises: a first drive rod moveably coupled to the first expansionassembly; a second expansion assembly; and a second drive rod moveablycoupled to the second expansion assembly.
 16. An interbody spacersystem, comprising: an insertion tool, the tool comprising: a handle; aninsertion end; at least one tube extending away from the handle andconnecting the handle and the insertion end; a securement mechanismcoupled to the handle, extending through the at least one tube andprotruding from the insertion end; at least one adjustment mechanismcoupled to the handle, extending through the at least one tube andprotruding from the insertion end; a first knob for actuating thesecurement mechanism; and at least one second knob for actuating the atleast one adjustment mechanism; and an interbody fusion device, thedevice comprising: an inferior member including at least one of a pivotcylinder and a hinge channel, a tool alignment opening for receiving thesecurement mechanism of the insertion tool, and an adjustment openingadjacent the tool alignment opening for receiving the at least oneadjustment mechanism; a superior member including at least one of apivot cylinder and a hinge channel corresponding to the pivot cylinderor hinge channel on the base member, wherein the at least one pivotcylinder or at least one hinge channel of the inferior member engagesthe at least one hinge channel or at least one pivot cylinder of thesuperior member; and at least one movement mechanism engaging thesuperior member and the inferior member.
 17. The interbody spacer systemof claim 16, wherein the at least one adjustment mechanism of theinsertion tool comprises two adjustment mechanisms actuated by the atleast one second knob.
 18. The interbody spacer system of claim 17,wherein the securement mechanism of the insertion tool is positionedbetween the two adjustment mechanisms.
 19. A vertebral spacer device,the device comprising: a base member having a length extending from afirst end to a second end including a first plurality of pivot cylinderswith an alternating first plurality of hinge channels, the firstplurality of pivot cylinders and the first plurality of hinge channelsdisposed along a superior lateral edge of the base member; a top memberincluding a second plurality of hinge channels with an alternatingsecond plurality of pivot cylinders disposed along an inferior lateredge and arranged to mate with the corresponding first plurality ofpivot cylinders and first plurality of hinge channels in the basemember, at least one contact area on a bottom surface of the top member,and at least one stop pin extending out from the at least one contactarea, wherein the first plurality of pivot cylinders and the alternatingfirst plurality of hinge channels engage the second plurality of hingechannels and the alternating second plurality of pivot cylinders toallow pivoting motion; and at least one movement mechanism engaging theat least one contact area of the top member and the base member tofacilitate movement therebetween, the at least one movement mechanismincluding at least one expansion assembly and a monolithic rod extendingalong a majority of the length of the base member, wherein the at leastone expansion assembly includes a cylindrical gear and a threaded rodengageable with internal threading within the cylindrical gear.